Electromagnetic switching device, for example, contactor

ABSTRACT

An electromagnetic switching device includes a housing and a plug-in module which can be inserted into the housing at an insertion point in a direction of insertion. The plug-in module holds a magnetic yoke, attached to which is a coil unit. Two extensions, which point respectively to the front and to the rear in relation to the direction of insertion, are formed on the magnetic yoke. In order to retain the magnetic yoke, a retaining bracket extending transversally in relation to the direction of insertion, overlaps one of the fixing extensions and engages two retaining tongues from below, said tongues being formed as one-piece with the plug-in module.

This application is the national phase under 35 U.S.C. §371 of PCTInternational Application No. PCT/DE01/00634 which has an Internationalfiling date of Feb. 20, 2001, which designated the United States ofAmerica, and which claims priority on patent application Ser. No. 100 09496.1 filed Feb. 29, 2000, the entire contents of which are herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention generally relates to an electromagnetic switchingdevice, for example a contactor. Preferably, it relates to one having aswitching device enclosure and having a detachable unit which can beinserted into the switching device enclosure at an insertion point. Morepreferably:

the detachable unit holds a magnet yoke to which a coil unit is fitted,by which a pull-in force can be exerted on an armature,

two fastening attachments are included, which respectively point forwardand to the rear seen in the insertion direction, being integrally formedon the magnet yoke.

BACKGROUND OF THE INVENTION

A switching device is known, for example, from WO 95/12891. In thisdocument, the fastening attachments have through-holes, in whichlatching hooks engage which are integrally formed on the detachableunit.

Further electromagnetic switching devices having a switching deviceenclosure and having a detachable unit which can be inserted into theswitching device enclosure are known, for example, from DE 29 01 552 C2and from DE 32 20 040 C2.

DE 26 20 210 A1 discloses an electromagnetic switching device in whichan E-shaped magnet yoke has fastening attachments, which point outwardand can be inserted into attachment receptacles in the switching deviceenclosure, on its outer limbs. A similar disclosure content can be foundin DE 42 36 900 A1.

The detachable units according to the prior art are all relativelycomplicated, with a comparatively large number of parts. They thus havea relatively high magnet movement tolerance.

SUMMARY OF THE INVENTION

An object of an embodiment of the present invention is to provide anelectromagnetic switching device having a switching device enclosure andhaving a detachable unit which can be inserted into the switching deviceenclosure. Preferably, the switching device and/or the detachable unithave a simpler design but nevertheless operates reliably, while themagnet movement tolerance of the magnet system remains small.

An object may be achieved in that a holding bracket, which extendstransversely with respect to the insertion direction, may engage overone of the fastening attachments in order to hold the magnet yoke.Further, it may engage under two holding tongues, which are integrallyformed on the detachable unit.

In comparison to WO 95/12891, this results in the magnet yoke being heldbetter and in a simpler fashion, while in comparison to DE 29 01 552 C2and DE 32 20 040 C2, it results in a considerable saving in individualparts.

If the switching device enclosure has a holding bracket contour on whichthe holding bracket is supported—directly or via the holdingtongues—when the detachable unit is inserted, the holding tongues haveto be able to withstand only the natural weight of the magnet yoke, butnot forces which occur during operation of the switching device.

If the holding tongues are elastically connected to the detachable unit,this results in the magnet yoke being fastened in a particularly simpleand reliable manner.

The other fastening attachment can in principle likewise be connected tothe detachable unit via a holding bracket and holding tongues. However,a physically simpler design is achieved if the other fasteningattachment is inserted into an attachment receptacle. The attachmentreceptacle is in this case preferably integrally formed on thedetachable unit. If the attachment receptacle is arranged in front ofthe holding bracket, seen in the insertion direction, this results inthe detachable unit design being physically even simpler.

If the attachment receptacle is designed to be elastic in height, thisresults in the magnet yoke being held in a clamped manner. If theswitching device enclosure has a receptacle contour on which theattachment receptacle is supported when the detachable unit is inserted,the attachment receptacle also has to be able to withstand only thenatural weight of the magnet yoke.

If the attachment receptacle and the receptacle contour first of allinteract via an insertion incline during insertion of the detachableunit, this allows the detachable unit to be inserted into the switchingdevice enclosure without any snagging and without being subject totolerances.

If a latching hook for latching the detachable unit in the switchingdevice enclosure and an operating element for the latching hook areintegrally formed in a sprung manner on the detachable unit, no separatelatching hook is required for latching. A bar spring preferably engagesover the latching hook and/or the operating element in order to provideforce assistance.

If the coil unit has a coil and a contact foot which is connected to thecoil via an intermediate structure, rests on a foot contact on thedetachable unit at the side underneath the coil and is at a distancefrom the coil, this results in the coil unit being supported robustly,in a simple manner.

If the foot contact is arranged recessed in the detachable unit, suchthat the contact foot is recessed in the detachable unit, this resultsin the detachable unit having a small physical height. If the switchingdevice enclosure has a coil contour on which the coil unit is supportedwhen the detachable unit is inserted, there is no need for the operatingforces to be absorbed by the detachable unit. The coil unit can besupported on the coil contour via the contact foot, for example.

If the coil unit is braced by the coil contour and the detachable unit,the coil is fixed in the switching device enclosure without any play. Itcan thus not oscillate freely.

If the coil unit has a switch which can be operated by the armature viaan operating element, the operating element is mounted in a bearingwhich is arranged on the coil unit and the switching device enclosurehas positioning and supporting elements, by which the bearing can bepositioned during insertion of the detachable unit and is supported whenthe detachable unit is inserted, the operating element can be alignedexactly with respect to the armature in a simple manner.

If the switching device enclosure has a recess on a side opposite theinsertion point, via which recess the detachable unit can be driven outof the switching device enclosure by means of a driving-out tool, thedetachable unit can be disconnected from the switching device even inthe event of a defect in a comparatively simple manner, namely inparticular without complete disassembly of the switching device.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages and details can be found in the following descriptionof an exemplary embodiment. In this case, illustrated in outline form:

FIG. 1 shows a section through a contactor with a detachable unit,

FIG. 2 shows the contactor from FIG. 1 without the detachable unit,

FIG. 3 shows the contactor from FIG. 2 from the front,

FIG. 4 shows a detachable unit with a magnet yoke and a coil unit,

FIG. 5 shows the detachable unit from FIG. 4 without a coil unit,

FIG. 6 shows the detachable unit from FIG. 5 from the side,

FIG. 7 shows the detachable unit from FIG. 5 from the front,

FIG. 8 shows a magnet yoke and

FIG. 9 shows a coil unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1, a contactor, as an example of an electromagneticswitching device, has a switching device enclosure 1. A detachable unit3, such as a plug-in module for example, can be inserted into theswitching device enclosure 1 in an insertion direction x at an insertionpoint 2. The detachable unit 3 holds a magnet yoke 4. The magnet yoke 4and a coil 5 allow a pull-in force to be exerted on an armature 6 in aforce direction y. As shown in FIGS. 1 and 8, two fastening attachmentsor extensions 7 are integrally formed on the magnet yoke 4. Thefastening attachments 7 respectively point forward and to the rear,viewed in the insertion direction x.

As shown in FIG. 1, the detachable unit 3 has a latching hook 8, whichis provided with an operating element 9. The detachable unit 3 can belatched in the switching device enclosure 1 via the latching hook 8. Thelatching hook 8 and the operating element 9 are integrally formed on thedetachable unit 3 in a sprung manner. In order to withdraw thedetachable unit 3 from the switching device enclosure 1, the operatingelement 9 is just raised, and the detachable unit 3 is withdrawn fromthe switching device enclosure 1 using the operating element 9.

For a situation where the detachable unit 3 cannot be withdrawn owing toa defect, the switching device enclosure 1 has a recess 10. As can beseen, the recess 10 is arranged on a side of the switching deviceenclosure 1 which is opposite the insertion point 2. A schematicallyillustrated driving-out tool 11, for example a punch, can be attached tothe front fastening attachment 7 of the magnet yoke 4 via the recess 10,so that the detachable unit 3 can be driven out of the switching deviceenclosure 1 using a hammer.

As shown in FIG. 5, the magnet yoke 4 is held by an attachmentreceptacle 12 and holding bracket 13. The attachment receptacle 12 isarranged in front of the holding bracket 13, seen in the insertiondirection x. It is integrally formed on the detachable unit 3. As shownin FIGS. 5 and 7, the attachment receptacle 12 has U-shaped expansionelements 21. It is thus designed such that it is elastic in height.

Damping parts 14, for example composed of rubber, are fitted to thefastening attachments 7 in order to attach the magnet yoke 4 to thedetachable unit 3. One of the fastening attachments 7 is then insertedinto the attachment receptacle 12.

The holding bracket 13 extends essentially transversely with respect tothe insertion direction x over the other fastening attachment 7. Itengages over this fastening attachment 7. Furthermore, the holdingbracket 13 engages under two holding tongues 15, which are integrallyformed in an elastic manner on the detachable unit 3.

As shown in FIG. 2, the switching device enclosure 1 has a receptaclecontour 16 and a holding bracket contour 17. When the detachable unit 3is inserted in the switching device enclosure 1, the attachmentreceptacle 12 is supported on the receptacle contour 16, and the holdingbracket 13 is supported on the holding bracket contour 17. According tothe exemplary embodiment, the holding bracket 13 is in this casesupported on the holding bracket contour 17 via the holding tongues 15.If the holding bracket 13 is sufficiently wide, it could, however, alsobe supported directly on the holding bracket contour 17. The supportsmean that the magnetic forces which occur during switching of thecontactor are introduced directly into the switching device enclosure 1,rather than into the detachable unit 3.

The attachment receptacle 12 and the receptacle contour 16 first of allinteract via an insertion incline 18 during insertion of the detachableunit 3, which insertion incline 18 is arranged, according to theexemplary embodiment, on the attachment receptacle 12. This makes itconsiderably easier to insert the detachable unit 3 into the switchingdevice enclosure 1.

The insertion incline 18 can be seen particularly clearly in FIGS. 5 and6. It can also be seen from FIG. 5 that a bar spring 19 engages over thelatching hook 8 and its operating element 9, in order to provide forceassistance.

As shown in FIG. 4, a coil unit 20 is fitted to the magnet yoke 4. Inaddition to the coil 5, the coil unit 20 also has a contact foot 22. Thecontact foot 22 is connected to the coil 5 via an intermediate structure23. The contact foot 22 is arranged at the side underneath the coil 5and, as can be seen, is at a distance from the coil 5. It rests on afoot contact 24 on the detachable unit 3. The foot contact 24 isarranged recessed in the detachable unit 3, so that the contact foot 22is recessed in the detachable unit 3.

As shown in FIG. 2, the switching device enclosure 1 has a coil contour25, on which the coil unit 20 is supported when the detachable unit 3 isinserted. In this case, the coil unit 20 is supported on the coilcontour 25 via the contact foot 22. As can be seen, the coil unit 20 isin this case braced by the coil contour 25 by means of a projection 26,which is arranged on the contact foot 22.

The coil unit 20 has a switch 27, which can be operated by the armature6 via an operating element 28. The operating element 28 is mounted in abearing 29, which is arranged on the coil unit 20. Grooves 30 with aT-shaped cross section are arranged on the outsides of the bearing 29and, during insertion of the detachable unit 3, interact withpositioning and supporting elements 31, which likewise have a T-shapedcross section. The interaction of the grooves 30 with the positioningand supporting elements 31 results in the bearing 29 being positionedduring insertion of the detachable unit 3, and being supported when thedetachable unit 3 is inserted.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

What is claimed is:
 1. An electromagnetic switching device, comprising:a switching device enclosure; and a detachable unit, insertable into theswitching device enclosure in an insertion direction at an insertionpoint, the detachable unit holding a magnet yoke to which a coil unit isfitted, by which a pull-in force is exertable on an armature, thedetachable unit including, two fastening attachments, respectivelypointing forward and to the rear viewed in the insertion direction,wherein the attachments are integrally formed on the magnet yoke, and aholding bracket, extending transversely with respect to the insertiondirection, engaging over one of the fastening attachments in order tohold the magnet yoke, and engaging under two holding tongues, which areintegrally formed on the detachable unit.
 2. The switching device asclaimed in claim 1, wherein the switching device enclosure includes aholding bracket contour on which the holding bracket is supported whenthe detachable unit is inserted.
 3. The switching device as claimed inclaim 2, wherein the holding bracket is supported at least one ofdirectly and via the holding tongues.
 4. The switching device as claimedin claim 2, wherein the holding tongues are elastically connected to thedetachable unit.
 5. The switching device as claimed in claim 2, whereinthe other fastening attachment is inserted into an attachmentreceptacle.
 6. The switching device as claimed in claim 1, wherein theholding tongues are elastically connected to the detachable unit.
 7. Theswitching device as claimed in claim 1, wherein the other fasteningattachment is inserted into an attachment receptacle.
 8. The switchingdevice as claimed in claim 7, wherein in the attachment receptacle isintegrally formed on the detachable unit.
 9. The switching device asclaimed in claim 8, wherein the attachment receptacle is arranged infront of the holding bracket, viewed in the insertion direction.
 10. Theswitching device as claimed in claim 8, wherein the attachmentreceptacle is designed to be elastic in height.
 11. The switching deviceas claimed in claim 7, wherein the attachment receptacle is arranged infront of the holding bracket, viewed in the insertion direction.
 12. Theswitching device as claimed in claim 11, wherein the attachmentreceptacle is designed to be elastic in height.
 13. The switching deviceas claimed in claim 7, wherein the attachment receptacle is designed tobe elastic in height.
 14. The switching device as claimed in claim 7,wherein the switching device enclosure has a receptacle contour on whichthe attachment receptacle is supported when the detachable unit isinserted.
 15. The switching device as claimed in claim 14, wherein theattachment receptacle and the receptacle contour first of all interactvia an insertion incline during insertion of the detachable unit. 16.The switching device as claimed in claim 1, wherein a latching hook forlatching the detachable unit in the switching device enclosure, and aoperating element for the latching hook, are integrally formed in asprung manner on the detachable unit.
 17. The switching device asclaimed in claim 16, wherein a bar spring engages over at least one ofthe latching hook and the operating element in order to provide forceassistance.
 18. The switching device as claimed in claim 1, wherein thecoil unit has a coil and a contact foot, which is connected to the coilvia an intermediate structure, and wherein the contact foot rests on afoot contact on the detachable unit at the side underneath the coil, andis at a distance from the coil.
 19. The switching device as claimed inclaim 18, wherein the foot contact is arranged recessed in thedetachable unit, such that the contact foot is recessed in thedetachable unit.
 20. The switching device as claimed in claim 19,wherein the coil unit is supported on the coil contour via the contactfoot.
 21. The switching device as claimed in claim 18, wherein the coilunit is supported on the coil contour via the contact foot.
 22. Theswitching device as claimed in claim 21, wherein the coil unit is bracedby the coil contour.
 23. The switching device as claimed in claim 1,wherein the switching device enclosure has a coil contour on which thecoil unit is supported when the detachable unit is inserted.
 24. Theswitching device as claimed in claim 23, wherein the coil unit is bracedby the coil contour.
 25. The switching device as claimed in claim 23,wherein the coil unit is supported on the coil contour via the contactfoot.
 26. The switching device as claimed in claim 1, wherein the coilunit has a switch, which can be operated by the armature via anoperating element, wherein the operating element is mounted in a bearingwhich is arranged on the coil unit, and wherein the switching deviceenclosure has positioning and supporting elements, via which the bearingcan be positioned during insertion of the detachable unit, and issupported when the detachable unit is inserted.
 27. The switching deviceas claimed in claim 1, wherein the switching device enclosure has arecess on a side opposite the insertion point, via which recess thedetachable unit can be driven out of the switching device enclosure viaa driving-out tool.
 28. The switching device of claim 1, wherein theswitching device is a contactor.
 29. A switching device comprising: ahousing; and a plug-in module, insertable into the housing in adirection of insertion, wherein the plug-in module holds a magneticyoke, attached to which is a coil unit, a plurality of extensions, whichpoint respectively to the front and to the rear in relation to thedirection of insertion, are formed on the magnetic yoke, and in order toretain the magnetic yoke, a retaining bracket extending transversally inrelation to the direction of insertion, overlaps one of the extensionsand engages a plurality of retaining tongues from below, said tonguesbeing integrally formed with the plug-in module.
 30. The switchingdevice as claimed in claim 29, wherein the holding tongues areelastically connected to the plug-in module.